The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 31, 1995
Filed:
Feb. 07, 1991
Applicant:
Inventors:
Jack O Chu, Astoria, NY (US);
Chang-Ming Hsieh, Fishkill, NY (US);
Victor R Nastasi, Hopewell Junction, NY (US);
Martin Revitz, Poughkeepsie, NY (US);
Paul A Ronsheim, Wappingers Falls, NY (US);
Assignee:
International Business Machines Corporation, Armonk, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
437 31 ; 437 97 ; 437141 ; 437160 ;
Abstract
A low temperature, epitaxial, in situ doped semiconductor layer is used as a sacrificial dopant source. The resulting doped region is small-dimensioned with a tightly controlled dopant concentration. The dopant layer is oxidized in a relatively low-temperature environment, and removed by etching. The process can be used to form a vertical bipolar transistor, where the doped region is the base, and wherein portions of the oxidized dopant layer are left as insulators.